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Old 05-06-2014, 02:48 PM   #21
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Originally Posted by denverd0n View Post
I'm not so sure that vibration would be that much of a problem.
I think it would be a definite problem.
That heavy magnet and piston assembly travel back and forth at reciprocating engine speeds, with no countervailing motion to cancel it out. If it were run as a single cylinder, as in the drawing, it would pound like a jackhammer, gas spring or not. The lighter the entire unit, the worse it would react to these forces.
Look at an engine's crankshaft, there are heavy counterweights designed to cancel out the reciprocating forces of the piston, wrist pin and connecting rod on each crank throw at a chosen RPM. Without them, any engine would hammer itself to pieces.
This device is just an engineering prototype, with no attention paid to this problem at all.
It would require a lot of loc-tite and rubber mounts at least.

I didn't mention it before, but how is the desired frequency obtained? It is easy to govern an engine to run at an RPM that makes generating the desired frequency simple. Maintaining a steady freq output under varying loads, without any flywheel effect means a precision fuel injection and air metering computer has to do the job.
I like the gas turbine idea mentioned earlier, if one can be built to sip fuel.
Now that would be smooth.
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Old 05-06-2014, 04:26 PM   #22
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I consider you right. Not intended to work as presented. It's like a schematic. Shows the principals and basically how it works but a ready to market item would be very different.

With 4 in-line cylinders w the outboard end cylinders 180 degrees from the other two. Two pistons up .. Two down and no side forces. Looks like perfect balance to me. But a long thing as illustrated w two of them end to end in line each 180 degrees out of phase w eachother would also be perfect balance.

Balance should't be difficult unless you want to make a real small engine like a chain saw. A really large engine would require slower speeds just like other reciprocating engines.

Actually an engine turns heat into mechanical energy but this "thing" turns heat into electrical energy. I think it's still an engine turning heat into reciprocating mechanical energy into electrical energy w a reciprocating alternator. What say all?

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Old 05-06-2014, 05:02 PM   #23
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It still converts chemical to heat to mechanical to electrical energy. It's just that in going through that process, nothing has to spin. Spinning things have little parasitic loss, so I'm not sure avoiding the "spin" is worth the engineering difficulties this thing presents. Still worth chasing, as with elegant computer controls it could actually work.

And balance would be an issue. It really needs an opposing cylinder. But that can be dealt with after the prototype test with the one-banger. Just bolt it down well to the bench!!
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Old 05-06-2014, 08:13 PM   #24
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I presume these three diesel engines in a Soviet Foxtrot submarine were reasonably quiet:

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Old 05-06-2014, 10:07 PM   #25
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A gas turbine genset running in the lazarette would provide a great deal of heat via its exhaust run. Blazing away at 700F to 1100F this exhaust pipe could be passed through a central heating heat exchanger to provide all the cabin heat a small boat would ever need. A long coil from the fresh water tank could make hot water on demand without costing any extra fuel.
I looked up gas turbines and found this on wikipedia-

"Microturbine systems have many claimed advantages over reciprocating engine generators, such as higher power-to-weight ratio, low emissions and few, or just one, moving part. Advantages are that microturbines may be designed with foil bearings and air-cooling operating without lubricating oil, coolants or other hazardous materials. Nevertheless reciprocating engines overall are still cheaper when all factors are considered.[original research?] Microturbines also have a further advantage of having the majority of the waste heat contained in the relatively high temperature exhaust making it simpler to capture, whereas the waste heat of reciprocating engines is split between its exhaust and cooling system.[17]
However, reciprocating engine generators are quicker to respond to changes in output power requirement and are usually slightly more efficient, although the efficiency of microturbines is increasing. Microturbines also lose more efficiency at low power levels than reciprocating engines."

They burn more fuel when unloaded than the good old diesel.

Siemens builds the big stuff-
Power generation ? Sustainable Energy in the U.S. ? Siemens USA
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Old 05-07-2014, 05:35 AM   #26
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>I would like to see marine diesel versions of Honda Inverter series. RPMs matched to load.<

That would be quite easy to home brew, a coach alt 12v 300A or 24v 300A is very robust and easily found rebuilt .

A welding throttle that simply holds a set voltage and a Trace or similar 4000W inverter would make the package.

For an engine the truck reefer takeouts would be superb , huge oil cap for 10 day operation and with dickering Yanmar or Kubota are 3 for $1000. or less.

All you need is the will , and a couple of grand.

>Keep in mind also that "better efficiency" doesn't automatically translate to "lower cost"; an example being the Gas vs Electic argument in home heating.<

While a toaster wire , resistance heat source is 100% efficient , todasys Mini Splits claim 400% to 500% efficiency as heat sources.

No free lunch , they simply steal heat from an area and bring it inside.
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